I think that ssh and sftp are all we need (should not need scp). So, that
raises another question... what sftp server should I be using? I am
currently using vsftpd which is supposed to be Very Secure, but I can't
find anything in the vsftpd or vsftpd.conf man pages, or on
vsftpdrocks.org or vsftpd.beasts.org, that describes how to specifically
set it up for sftp. Perhaps it does sftp by default, but I don't see any
config options that would enable encrypted ftp and disable plaintext ftp.

Wikipedia tells me that sftp is more than simply FTP over SSH, which leads
me to question whether vsftpd even knows about it (the name stands for
Very Secure File Transfer Protocol Daemon so I guess I more or less
assumed it should...).